} 
30) University Geological Survey of Kansas: 
bon dioxid, give off hydrogen sulfid. This may be considered 
@ common source of hydrogen sulfid in so-called sulfur waters. 
3. Solution, as in the case of salt and to some extent gypsum. 
This solution is frequently very much aided by the presence of 
carbon-dioxid gas in the water. Gypsum, for instance, dissolves 
in the proportion of one part per 1000 in water saturated with 
carbon dioxid; but it dissolves in the proportion of about one 
part per 400 in ordinary water. 
4. The formation of carbonates, as in the case of complex 
silicates like feldspar, which absorbs the carbon dioxid from the 
rain water and forms carbonates with the liberation of silica. 
By the process of disintegration, clay, a hydrous aluminum 
compound, is formed, while nearly all the other elements of feld- 
spar are dissolved and carried away by the water. 
5. Hydration, as in the case of minerals like anhydrite, 
which by absorbing water leaves gypsum, and some iron min- 
erals, which after oxidation take up the water. 
SEA WATER. 
As without doubt the original water upon the earth’s surface 
was sea water, in the study of mineral waters it is appropriate 
to study ocean water first. M. Antoine D. Saporta™ says that 
the taste of sea water is due to the presence of salt, and the pe- 
culiar bitter taste to the magnesium salts in the solution. It 
was once held that the bitter taste was due to bitumen, and, in- 
deed, artificial sea water was made in the time of Louis XIV, 
and bitumen in small quantities was actually introduced to imi- 
tate the taste, but M. Lavoisier, more than 100 years ago, dis- 
tilled sea water and proved that there was no bitumen in it, and 
that the bitter taste was due rather to magnesium salts. The 
ocean may be considered as a great inexhaustible mineral 
spring. The ingenuity of man has been taxed many times to 
obtain pure drinkable water from the brine of the ocean, and 
numerous ingenious devices have been brought forward for 
this purpose. Practically, however, the only efficient method 
is simply the boiling of the water and condensing the steam. 
10. Pop. Sci. Mo. XXVI, pp. 529-541; trans. from Revue des Deux Monde. 
